The present invention relates to rotary switch apparatus and, more particularly, to a novel solid-state rotary switch utilizing sensing of the perpendicular field components of a rotatable magnetic member.
Mechanical rotary switches are well-known. Typical multi-position rotary switches of the unsealed type are easily contaminated. Contamination may be avoided, and reliability significantly improved, if the mechanical rotary switch is of a totally sealed construction. However, such totally-sealed mechanical rotary switches are typically both bulky and expensive. Either type of mechanical-contact rotary switch also requires many assembly operations, as multiple metal, plastic and/or ceramic parts are required for the construction thereof. The labor content and/or number of different machine-assembly operations is therefore quite high.
Optically-encoded rotary switches have been built to overcome some of the disadvantages of the mechanical-contact rotary switch, but also require a relatively large number of parts, including several pairs of individual light-emitting diode sources and photosensor detectors. The several parts of an optoelectronics rotary switch require careful assembly alignment for proper operation of the encoding switch unit.
It is therefore highly desirable to provide a rotary switch which is not only of low cost, but also of high reliability. It is desirable that the number of moving parts be reduced to a bare minimum and that automatic construction, including component insertion techniques already in existence, be utilizable to minimize switch assembly cost.